SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a714ae93eea900a88a92cca41902f2e0375411644e56767026ff4c004048a8a1' 
  AND token = '5MIVFf/huoFXcAR7V3v3PNvVqAX4vD1Y/wdzF1nUBCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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