SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d2693f73522726e58525a91f272f863e156544ac17933db0cb37545ad11ba31' 
  AND token = 'jMNjls70y8dKXdpfNNoj1+8eC31wu2bN1ZzQqGjNL+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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