SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30345daa8ed2c528506ab7e2bc496085b9b0bc301c95a4dd959dd8feab122a74' 
  AND token = 'umcHcF+XgHssuZ3iIWFPwDyS0L3W8om7MeL9u/d3xPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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