SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26e92bdf0dd60ad0b0a66c792dfc4bb0a08aec3d301233ea83a674a7a93fa96d' 
  AND token = 'eu14vhEq3/dToOtfofrJohh5qEjaYmZ9Gu5fAKrRF6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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