SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '158a4a63a03e9bde8fdd4a011b6e168a3fd3f2958af4124fa7af2525aecf8195' 
  AND token = '3mNTKM6KT/z1lEIz2mctUboTWByMNzzOjLeSrqZgLr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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