SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8c28624dde55cd658dbac06ab0881ff13e2f1c58612feae31b10ebe98739730' 
  AND token = 'n76OWxNXfnMxfFZOLd3xHVEuYeRfpkIPNnZEnPX5yRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}