SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '529d698a4af4d648a5739a2ee1a5648fe3d8d5bb8ab3c84846abb6481d87d3cd' 
  AND token = 'yErKMVWz/V8wUuQechtQDrWNXQxtTaHGHQiq6GcheGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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