SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a396d46d86f33517df78f88ffa1146492895b97d24f7a91807843a228bf94817' 
  AND token = 'U8CLbLoa0naZlvVkmFLknq+oIUO8G5VwQjyaTgLFHns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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