SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '507c1fbf2aa1926bad06964a55c73eb36a89d819736d13bd4e308fb9d287d50f' 
  AND token = 'wU155uzo1QfiatqgUIO44hBxasMfys9/My4xQIvYuSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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