SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3031631bf0aa52d7fd13876bd0371119ecbf6d44079fea20d76bee8bd14e77bf' 
  AND token = '4rIKABJ2pjQUBXKCZRGaIAaf4l8X9OZRzD2DdushN98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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