SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf0d877ca7b292c7d0699b02280c06076c141597ac02bbe8cbd6936fbcb24894' 
  AND token = 'idrzIN7zCGpHZyatIz2FYbc+Zgnycl2wzFJ4CFIw83o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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