Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e21de88d5297fec48a3a0fa79cecba1b0491bce693c85780d61a09d1904f4eef' 
  AND token = 'b703XeWl671aParSZoZVQfgXtthsBVi913PvptdUrRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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