SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77a987557051c408132ac8648b6c4747d35ab19334b314afea3eba2b4a73e6cc' 
  AND token = 'vV2ct15WS+HTOK4kSRXbGYHEIis3rGVjryIc7Ht94/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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