SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa9e27d55a87a229d1bcbe808e928627b7cbd78affdeb3f7a76b1f9a30d71f9e' 
  AND token = 'CCm6PwZZWeB7wuW4BBR3uClh35t/uTz7jJyvjauEGZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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