SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '679ad30a5ed1bb0682577c1ac7e60aef6a0ed5e0796cfc478ccbb729d5b9613a' 
  AND token = 'vdRtIMLavajbh0xyvoLMICrJDbasapPWegEEGrLXLWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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