SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaaa2bfa9b96ea4c011f3c9c1d84d894f78626d4ad28bd01f11af9423bff22d0' 
  AND token = '0TPoLFU62jAPvHV4WhdmrITM5OUabKlOQr/MBknrcng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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