SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7d341c962431f8c26a3deabe24857deb1daa42e1ac08e450f57bc9b51f2d572' 
  AND token = 'U4YtKzOn1rkOLqgTcjwGv27Z26hndqke+rzseJsoFZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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