SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04525f87949c2fc24436474bce50e9e1bd30208a8ff745679a70e3b36745b4c0' 
  AND token = 'NCNjNqEs0UuJJchWydhUTs3B/Pn1qV+GvZP7cNuuB+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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