SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '358f721f26d5abc2835246c62e63f45ab2d543c16047e29484cb17cce25d9b15' 
  AND token = 'p0KMgs1lhw2UU73hsPSzF0N8/JTajYv+/3/uxj7Nv6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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