SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9595164c4a5ff52b2ef340d61471687bb8b8672f581af3c574d5f018cc7f1b9' 
  AND token = 'gf/6PxXwjxzo5nEiQW+gg/InhnHrx/PACVEAEZ3TfVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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