SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3381c63dfca5ee6c58d51e4618fd610ee71bfca7aa63665fee1977dcd019957' 
  AND token = 'cvivesvOlxctEbJ3+VrZMlYmrapzFDDp3onPsZ+aQNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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