SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '815430ecf554e0ab2abb65ead1db34446ad949487e25f89b852deb8757f0b84f' 
  AND token = 'jfLSJGt/U7F9MlwZd/30S/XPGoYqp611WQVmY7mRmkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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