SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc62ed5a5e6a6e32162f235588b58c4bb558f9473a01b0bdbd93d7432c458268' 
  AND token = 'w3gwQbcIV+9SwMp3UNqWGimmvZTZMi1YjzOU0mCpUi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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