SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1172337f2c7881b78f1a5a7d029b6aa2331ca071851bb25e0a9dad386194846b' 
  AND token = '+YmCWsYpW4+FTrhRQDH3V/F73J5xcju95rBNJlVzkV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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