SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02321d5a1de3aa027611469132efa0b750c7f5b126178fd48e5f14de2d0b5cd1' 
  AND token = 'nloNlV/pKbR/wdshpqKuZriwKiO69QLVmDOksseBJjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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