SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5758011543d48f174158416e08b28fa54427a0f4cca43d541605625cdf88c95a' 
  AND token = 'jZnGVc4DQqri/pA1MiryfW1POgQV13+9ta9eL+G3u2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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