SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27abca46349bcf5c01c521c9128c66d81435279c1ed235dfd3ae00d21ec0354e' 
  AND token = 'cu40tfRVFWIcXiyI6gbUtbONT/RvEDjs72QJTfVMmXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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