SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f04c1e2c065db1b466b8542fd94d0a280f39f517a6cd9533a315090387affc7' 
  AND token = '5FjSKhjAyElea0YXlbhCjEypoKfYSugzqt4ZWLGHRv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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