SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a67598bbbbff59ea5d553ab974aef38a7355c1a474ddf30a934a01d4c82d38d3' 
  AND token = 'ahz06h6XQrUcgavKYRTcepRV4qcBNmhalysRofbzp0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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