SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b895e73c5624e1e5fe4703ba14fe9288bec95822bdd974d42ce15ac29fd42e17' 
  AND token = 'zJsF/nQgzawDhjxJM0yCNoDvRGwvfGLIZRMwbq1LcIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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