SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f29221bee965bd2f75e20464e01e08061670bea1d70c028dcbbefab99ca6053' 
  AND token = 'xvlCHa5r4up+tBxjEJHMHTDLB/WPOD/gyhj+qbZWIfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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