SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'aa5eb5553d6dc72469af39553e938099adbdc720911b160d5505ff037400a3b4' 
  AND token = 'gXh6lWd7D1YIj8cqhbwhnmEjdr8dq7HRj2DpcuGXKRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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