SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '93ac36039a209a947818b4f999a86432d74d5cc9cb138c625723c82db3f77ba7' 
  AND token = '684PwT94wsWZGUvhPqvGd4Uq0yHs5QJ7ndC3LK2A6sY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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