SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbea51b5bf20b814c63fb723438c320de9682de885e16b5cab819da7769bf164' 
  AND token = 'qtYlsh7tEOKpzOkFkbXyXFp1xYQK2PAGwyyUmBkCOnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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