SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f94cfa6f02621fa708ea227486adce9f5d313267899cd32ea52d0b728d085c9d' 
  AND token = '9E5W2JdzhWg14klZ+f5HKhOsox5vRP39RyhmJfbg1zo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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