SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59539b1d7bd8196e87af93cec7ec711ac727fc9d943816991657114e0a47296b' 
  AND token = 'lqkl3+1KC0fw5A1acmeSHbTi9UgvStCfVUjRx/MHdsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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