SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5484ebfcd7a8905ea3f921cd64faf32f1dee917ff861b32d945902faa7166be' 
  AND token = 'KCoOtQL8NV6OfgIRPX72RPEAlBkTj06xQkWrBYBSyYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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