SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3c9473ff242505f23e76da507cb1ee4c82b73537deb833dd8ae5fe76f7c5e42' 
  AND token = 'tIgLucT76IRx+2bE6GM+alJO4d5y3Bu+rA2LuCE+sZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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