SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'dab9dc2882d045aa4b1f597c241bc879f2a58f5e97c70956ce9c46ab81125238' 
  AND token = 'K+xSfULLkQ5Wo3VekAA8hiG+rKcqIrKLoJdkTDuQ0Bo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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