SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e7049d1752f8995f604bc03de50ebf897555934609d91b9d81157613d979c653' 
  AND token = 'N9yL+Uag23S3refIrpIZUa9Ye+dA2g+8lTJ5OK4qWy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}