SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '864f1e54da0e4592ad7325f5cdf198cdca8c189dd9463914609e9207e8464841' 
  AND token = 'yPv905/KMMu0jncYrMcKzszxEowYHt+7ipjifVQI3xo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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