SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec20d94a426785a87cb0f252fb0d7a597858c76773c7064858834c545213e28e' 
  AND token = 'sBNOGUltu5y3cq/Q1yJc2YcirgbNUzzFw7CMmyivVoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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