SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e84a6224b64296b7c35f34b5672048094dfd2a3c185eda815d07ed389ba0207' 
  AND token = 'MnqJw1qPWLNxQSrWUkzH0EvZR6NOFHgV9isrCFdmZ9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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