SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '847af0ca9e1e035a7344eef99c1bec422b3165142f9a5df843c23ae16a65046d' 
  AND token = 'xsvz9MpuWahDauD119Sn9BMMoNNLCHxuZYCCnK9R0jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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