SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c9acefc5001af8ffb88bf74bc9af9e66b9ee98597a4e4c13812bf9c592305dac' 
  AND token = 'P3SmfWd9gWH8rTqk0K1CI9ZmXxHsg8JIY0JvWoX1tP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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