SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '948a5893203da0867d4699525a44232dbae9193a9adb453eacb6997bfe76accf' 
  AND token = 'kFni4Swsi55OKU/YfrxwyTuOtJ9TQgbuOKvzbuOpPoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00106

JSON explain

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