SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88f2181517ee73f9ced742cb014db055edab7fcad82bb04afb0626c8e8863bca' 
  AND token = 'j7LGmw95DalzXyquiOq8epTSMNlEqMzbvF4243FmYSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}