SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b16bf7fda2e479412f0d6f1922158168485ce5d9dc54a95fa45b18d3839fd2ac' 
  AND token = 'Z4Nr5G1QPohqDS/psKozmPi0E+oMF/uy0Lxw8UHup9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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