SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '748b1e2a511d3f137da9ae1002b5f2b2d4566d5f02250d39f1a48c1e7c5777c7' 
  AND token = 'S99oROryNLX5uhTpAKDxphisrKtWUO9qoqFWV+Tmvf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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