SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '718f9ef67c5f7394eaeca4faf6331786fe03cfb821009c626b873c48fd340e38' 
  AND token = 'cbQqBrVF/ppNRV9BJozJsQe235r8kFS1NVS6d9ZtRZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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