SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93eaef2d537a12640c3489c89046109698c1a9177502ee9ac666f521b06b3bea' 
  AND token = 'M4D1gHqu16bcekAP7Kx9ERadOAoAqhRqxpDBrkpOelk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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