SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5758ed9bdd7fc8ebdd82695b0d9b84af7b9e737c9869c541bb0b63c55995172' 
  AND token = '+vDgQr1TJ8+EuVPBLcgupDVj2G8CpyZ5m1fu3T/dzu8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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