SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '074d9c642b4e15c3588435d2db6dc72639d6ab6068691a68b42a7d2a1be1686b' 
  AND token = 'O1gnfguq/rtVp7oWwGum+6N9Or7hqZQGKWZ+kMhYfSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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