SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc2e64c4e8b1e7e19a5250501eea89c7c18b0ebdfa05369198006cf7857e2dc7' 
  AND token = 'vCfDsZ4oIA2SiCoNU0yl3bB9rubAfXkzISkyuYh0Xr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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