SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '663a8af70867dacbce54c52334b2d7f71bae8ef28236bc66b291477893060e52' 
  AND token = 'VkO8vixiY3Wi1JBzAHkrXSS3zQAbN3nrVjAgfI5QOfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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