SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '185b31ffd0e29fe12c36853b7438641267e3ab1df4ae5601c8a14261028d989e' 
  AND token = 'mP25dPZdJVwbO2rWBgQ/vwhHsdEyIH9Z65EQKRFkSjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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