SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dbae551067620e20c50d9913b7cf966ec30f6873f77b9c31c947ea64ee2cfc9' 
  AND token = 'IvWpRMkkoR4xekLgDcRSo1XWv/T7wfZZRQabw5LklYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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