SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faf3ad398d2d3c71407c22fd9227b4c28ad72d9155e462955afba69a95c9f4df' 
  AND token = 'a73OYKiQwLBAZhP7n0QUlhkRkf3RFJ64oiMlFXd8WO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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