SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da01d864d8a670a792b9c6add3e5bb64202e17f4f6c24971f90905484a301560' 
  AND token = '7Fq+vmQjFtZRzC3EjHJY/OG5pZ0WOVLQhNicyhfVrAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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