SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63bc1848e9818460f8b79a02952a68d3951677d706e2fe5ebc758daa8b4fbeef' 
  AND token = 'C8lTJaY48tAAM8IzQc1lUHxW0C+H16TPGo3jcofBDaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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