SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '447e285810113966c4a384cea0d0784c331bcde63fc0108e04eadf02dcd75d8d' 
  AND token = 'b7B0UyRJRaCYUKQdQShd9OM0zLa6L2cpjrXftiJRAAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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