SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db37aec4f35a9ecb6b42f9123a23ba258e0f7b9f23a52258556600336c1acafc' 
  AND token = 'Trg7upxYJOCesYfZYoqi6I1KD2v5lGXORqBkRwR8VAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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