SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e04dfd9ff58f9158e199890729314dcefe7a698258207acaa007a654834cc94' 
  AND token = 'x72LCk/hlIOzcHg77QsgTeZSgYybDaOXJG+k64mMKqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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