SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '522790a25332aa684d0aec3fa85ee7747a68025d31a22bd19e6013441cd39b7a' 
  AND token = '7Ostig8GztMijWA5wpZOBxslvx2njQHZHk40XtnMh+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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