SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbeb2ca393c3a98753049a6354f63c40232457fb4b709151a30dcc7caedbf911' 
  AND token = 'qDx3xo6N8Zc0n+wbNFrEGS5sDvC6jUHvCit2hUCPDcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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