SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c65da517a937b3ac84905a1aff1ccbad614521dd51904a314ca1c51b1938108c' 
  AND token = 'qZeX4zybz7gPHRSP1wu/sBVvAzR/5cEhNnGCq+L5YBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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