SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '035892bb1e5f791a91baab168e5bf7a45d0715f06fd3206a05b7df0318c4abba' 
  AND token = 'vKyRllQ0fQupCpOV06tn2qaC7KRG37ZQI9JRGdoMqHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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