SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '65e5e2140bd71baaac87dc4e31287c9b9c573fcf2985d3b2b1ef0c1a95378d01' 
  AND token = '9MZ69EjROyBHBbAV0YC0ZdeLchr9htOj89iPNfGchxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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