SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f88386c70b0802073a8b914a635580f5a9a6380c4765d76a4a46d0a8e289fac' 
  AND token = 'HXSJ+HvvX6GwutJrOgnxZ1b/m9Uzr4VWf+rJbbdmYGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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