SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eef9f6b2210b4afbf0232ad5e8dd647ca1e78ef1af5a4b3971e7ec556eee7692' 
  AND token = 'DVD/2W4PSvfujbqlTaBkG4yqzPcg3sW+JBRB2a9B8R0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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