SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c25b07b2b36d9698f239f465897bc334554195abc594db1f0f79aa2b820d6976' 
  AND token = 'ZfAFxbNCO8O8IQRMj2RsupWVoHVftXI3bE5TcGeZOhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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