SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fedf5597a828166b85c80a0d4e7a6ca2e1792e59f24df0cef7d6b8b178dda12b' 
  AND token = 'BBG8gc5hqfqlVksw4qnUZdI4gO+fnVR1jA8slXqpnvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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