SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b11ab95ab1544eb17760cfb181584980e51c716cbe49ec6f29197b5edbd9a9eb' 
  AND token = 'bzumio1uZ5CRtf2EhbBBcWpnUdHuIRYyKdsH3+SZTR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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