SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75587b3504c55da10cd037acdefcaf709358859120812b9ad20ea3e7472e1eeb' 
  AND token = '1lgm8iNFQoHmulBegafFkU80IacX8I0TjGeK1ix5wps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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