SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '219e5e8082224dc47e56115b1875b01a609021c802dbad06506d6f6c3c726a01' 
  AND token = 'f6FD3THTlkXfU/Q67wdwNySDemgqbLwNKmeTuK7EUBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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