SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '574d7ad31c959c6707b6c52ccbe172f4bc2d89ad8daac7f207e64b0220c43d9c' 
  AND token = 'QkXutUvxL5DuJ+9N+h3thUoIAFaARMwKmJjnnfZMYLQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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