SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14876b2312edb30b537d8c1b123133d180870974baa7c93a7eab8fd6f16a5c34' 
  AND token = 'iqdqyUJ6/JB5vwQi6LLQaU6GErKg/fmNKB94pR4pTwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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