SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45644c5a9e1a9d96bf601522b7b3f7bb908a3221c7f07ea482066d4c2da66b2f' 
  AND token = 'qo1ZaRvZuhJJ9Jtbgq5hnxi1Uc9ujV+xeIdXnm+8+W4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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