SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed40f103c5dc4329c9e575330368fa47ddfca720bdd3173d50d5f18c96071f85' 
  AND token = '6a83DDtgIqfLZEkXXnHnAffIc4Yy2fBi9BGB+/Unb5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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