SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de41d88cb7c720f22315279c5b08a6ecc08ed3efcc1cd88fdfbb28414d3565a6' 
  AND token = 'IVzUgZxromKBxnhBAYOPqj5NdA1RFnl8/fDq6mlGgqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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