SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb6e08164c4f5225e817530e9035edc612e16e338ec28e559951ba1c7c822dc5' 
  AND token = 'dlWNg41zCHOscxgok7xgZ9/whi/RGv7IBOVDQ6ZgtAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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