SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef95f9f796e4a20d9a4717e60fabe9bfd3aad0607cbb7d83238fa1b46f222bc4' 
  AND token = 'NTfi5OOmRuHpxuyoLtXBmP8hSBgucXYhROneaUSbTp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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