SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc7d566a5b6ab7d0a8e711114b98a76f801c5bb09c693b092174286017c82ca1' 
  AND token = 'aGj7TYdaKKHMzCLW26tvjgtWG1kBaD+DipWC/fqnw8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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