SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87c2c2fc072b13228eaeaecef5ca688e5afe34e0478474c864f6c0045b5d467e' 
  AND token = 'bQGmhslY4zOb0kmDI2JfFuyNEFVifKZVRzZaHTos7as=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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