Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7f997a5049e3a7b17300231f85438d96581f16d78603265716f9d298665d0da' 
  AND token = 'MfORujnlJxf7NMM9uMZoFzej8VV871AFmQtVo2CTQ60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}