SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96c310d3874181c846f622f41c6fc10fbf9c4c4528e3594c0849b2e178693cb0' 
  AND token = 'VAEBg2nBkWIYni/cj4bEF/jQMvv/NyqeUVaijopW8Iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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