SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e216282a4efb188c054682d67b0f40963c9fd66f7f949642b1d473e0fd0bf427' 
  AND token = 'ddXzxezZJ9ZYD2o2CqfxUpOWkrVOgqgeRX3FlrzJdEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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