SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fd9c124ab61fbd32143332cfccc4b052606c641ee92fd5d8b8b379e88f5ea3d' 
  AND token = 'TB3ibUAAWb7zKMaZAWZxehepp0Vy0QTJO8JpCsxDO2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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