SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b69f5baebee3e619f1fa1d03eb1397608ba8b0a686b2b318a2ca9170411e6ebf' 
  AND token = 'NisE4CCw4nZiFjahjE6Wi5iKIBWhM4FolPDdhSvbvKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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