SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '602cd5edf61e645528a0b142fb5e813334b202ecbe363131eed863ab689f7045' 
  AND token = 'Uxhd/qmsshq7Y1CQEf48ek3jKfTddiFZylsCOMG+ZgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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