SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af7f4f4b66d36abfcd7e934ffb47ea32dcd823df9d2a33840c8e1ab92e545124' 
  AND token = 'BIwz/MR/7CqeXGxsS2RviPrGW8LCIuiEvuThSQun0eQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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