SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '051162cd7277b4b42a9b3376d2c8bd6aea2f5f1009de6436a117940ffc77df9e' 
  AND token = 'DHqAthIoAzBCNZip+wm/ukt2xj0oxD2jTSJioJWrNCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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