SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e3805cb2948d37f580064394a405fb4600a0cbb66b66cbbc9cd564dc0ef4c0d' 
  AND token = 'XeEYy31ZlrO6Jxg9XryEzKYxsRVgwGRcY5YxOuDXgaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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