SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62a111e5d2ad36af5e1346d73892a3864d375cb6d211fac3ad8d71691d095028' 
  AND token = 'wP748dLCJ/DnJb414dM+Zt/9k7Ee4Zym2BuCMAjTfXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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