SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '472ef691281bb10296e2729d713bd334bc7bad784ca2baacea7de6577faa8826' 
  AND token = 'xPamLjMzISosyd92h/MgOkFsV2BOg0P6owOZ8bjCa08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}