SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5728ec5f1ea0e0ca76c75fc179db06de78816298d9ffe9a9532cc0f1a6c5b556' 
  AND token = 'bCqL1jJx1bANY+n46fM0I+EjHbCmKHu9Ysp6TrWsc04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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