SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32d3d9c466bf771cfa6e0e70fc4c235a8ec594fa87c99fde65fd0785445e0483' 
  AND token = 'S4lotd7vPpdNWP7bsYWW0s1JLvp1csyPLGICmOtuZks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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