SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1eceda2493fa0e3ef8bc3cedd96c51607c5ac8bb843117e8199b72fb44359d4' 
  AND token = 'hVnjMGdxNH5lFrPbExuEUj1vFHd5nADrTKspFOIBGVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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