SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad0f219e807d92200ed63fcb424f9ca6c975a14c7a896189e8748d0baa311eb2' 
  AND token = 'B5w5bFrB4WGkDm/3Koaucb7Y8hBh0WyrpS05wokeI70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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