SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98f68739f2049e64b3e3ab88cbe679b68d511bf1069cf82401626b9b2375c5b8' 
  AND token = '/sgJDRuh3ziFuRZ9+OvZA1WpO8MtwWjv4Tio8FQSfpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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