SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a33dc4c6fac980c9abf23fcfe7d52b7884b633eb17e0e2416da526cee2f23c7d' 
  AND token = '1WeKdyddIqywqpQZpCbqiYoJ7WhITzHOxio3x7RQvqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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