SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9040de1243d4078afc0ce05937c9db0ff83445a9e6d6dffe693ebb231e9b89f0' 
  AND token = 'qG5lFQSOQVhK9PizwL3HNSZMAOJz9svUNfarrWtS+rM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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