SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f56b551e8f097e176a37a784da548e17ec7f43e2a9ef43ecb4a440ccce4b1a92' 
  AND token = 'ntfihbmy58jv1AYID2kv/XpnNWpbhNaCiQZ6BZgi3S4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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