SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '328bb5e33fef6af1145005529d7dc26861a534a73ec75ace2f591393337404a0' 
  AND token = 'INc/MX+dsUN5kgAzPMILiTVxpCeE2cnUonqQYQb129w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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