SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3270d36f3116264d74b6faa92a9fa069dcdf8310d7b86802a72868828bbd04a0' 
  AND token = 'rAVoX/QMeQZ3zhsZTIaKEZDZrdj6NtJ7hvLsipqNcD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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