SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82972c7f2e00c14dc7940e12269361991bf20697c4c8a74d69d02544447c3266' 
  AND token = 'WmkGZzsFNKLQ+2IZEjuZA3i3SOtY60A0vlg5pecm+Po=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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