SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e0cc50c2df25ccd1a18a0c7e6d76da1b1bcbd93279ea498a837730b1201d3b2' 
  AND token = '6lxa2YRTkdNiZNPU8Fi3cJpRiprfadHNy8OulNHnjcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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